The present invention relates to a dual type vehicle air conditioner comprising separated air conditioning systems.
Recently, dual type vehicle air conditioning systems are mounted on part of luxury cars, wagons and minivans (or one-box cars).
A vehicle air conditioning system of this type includes a first air conditioning system for air-conditioning inside air and directing conditioned air toward rear seats, and a second air conditioning system for air-conditioning inside and outside air selectively and supplying conditioned air to front seats. Each of the first and second air conditioning systems includes a heater core using hot water (engine cooling water) supplied from an engine as a heat source for warming air.
The heater core, however, tends to become insufficient in heating ability when the outside temperature is low in winter. Specifically, a lean-burn engine generates less heat and the heat quantity of engine cooling water tends to be too small.